Sorry, but the bonus dice rule seems vauge, can the damage dice that you roll ace themselves?
Or is it only the to hit roll?_________________"I say Mr. Chesterson, is that a giant ether squid following us?"
"Why yes it is Mrs. Monns."
"Well guess we should get ready to receive it."
"Blast I hate squid for dinner."
"But the cook has a new recipe.."

Sorry, but the bonus dice rule seems vauge, can the damage dice that you roll ace themselves?
Or is it only the to hit roll?

Not sure which rules you have as it's odd to have this noted as "vague" as it's actually one of the rare repeated rules in the book, but yes, damage rolls Ace. To note the references <italics added>, it's stated initially in the first sentence under Aces (pg. 62 of SWD)...

"All Trait tests and damage rolls in Savage Worlds are open-ended."

And under Bonus Damage for Melee Attacks (pg. 67), it says <italics added>...

"The d6 may Ace just like any other damage roll."

And then on the same page under Bonus Damage for Ranged Attacks...

"This roll may Ace just like any other damage roll."

And also somewhat under Bonus Damage in the Damage still on that same page...

"If your hero gets a raise on his attack roll (regardless of how many raises), he adds +1d6 to the final total. This roll may also Ace!"_________________Clint Black
Savage Worlds Core Rules Brand Manager